This specification relates to augmenting the functionality of a device using a virtual machine monitor.
A virtual machine is a software construct that appears to be hardware on which a guest operating system and applications can be installed. In an emulator implementation, the virtual machine is an emulator, simulating all of the hardware used by the guest operating system and applications. In para-virtualization, the virtual machine allows the guest operating system and applications to run on the host hardware, but requires that the guest operating system be modified to use a special API (application programming interface) to run on the virtual machine monitor. In machine-level or full virtualization, the virtual machine allows a guest operating system that is implemented for the underlying host processor to be run without modification.
In a para-virtualization or a machine-level virtualization implementation, a virtual machine monitor is used to bind the virtual machine to the underlying host hardware. In some architectures, the virtual machine monitor runs directly on the host hardware in a hypervisor configuration. In others, it runs as an application on the host operating system.
Platform virtualization can be performed on a given hardware platform by host software (e.g., a control program), which creates a simulated computer environment (e.g., a virtual machine) for its guest software. The guest software functions as though it were installed on a stand-alone hardware platform. Platform virtualization includes the virtualization of specific system resources, such as storage volumes, name spaces, and network resources.
Additional software is often needed by a guest device using a virtual machine in a host device environment to augment the capabilities of the guest device. The additional software, however, is not always available in the host device environment.